The present invention relates to protective helmets, and more particularly to a device for stabilizing a protective helmet on the wearer's head.
Various suspension systems, some including inflatable padding, have been used to provide shock protection and fit in protective helmets. While such devices have served the purpose, they have not proven entirely satisfactory because there is still a tendency for the helmet to shift on the head of the wearer. The elimination of the motion of the helmet shell relative to the wearer's head is critical in some applications such as VTAS (Visual Target Acquisition System). VTAS is a helmet mounted aircraft weapon control system wherein the missile radar system is controlled by the pilot's line of sight so that radar acquisition, lock-on, and missile firing are done visually. This is accomplished by computing the pilots's line of sight by using sensors mounted in the helmet shell. If the helmet shell shifts relative to the pilot's head during air combat maneuvers or under high acceleration, the radar system is no longer attuned to the pilot's line of sight and the system becomes ineffectual. Thus, there is a need for a device or system capable of stabilizing and rigidizing a helmet on the head of the wearer. Furthermore, for those helmet suspension systems including inflatable padding, such padding is generally designed to maintain a constant pressure within the padding. If such padding is used by an aircrewman, the volume of the padding, as the cabin ambient pressure varies with altitude, will also vary.